1. Field of the Invention
The present invention relates to novel peptides, derivatives thereof. The present invention also relates to salts of the novel peptides and derivatives thereof.
Also, the present invention relates to a strain belonging to a novel species capable of producing the novel peptides.
Further, the present invention relates to a process for producing the novel peptides.
In addition, the present invention relates to an antiviral agent comprising, as an active ingredient, at least one member selected from the group consisting of (a) the novel peptides, derivatives thereof and pharmaceutically acceptable salts thereof and (b) the strain belonging to a novel species.
2. Description of the Related Art
Microorganisms, e.g., viruses and bacteria, are known to be causing agents of various infectious disease. Research and development of antibiotics, etc., against bacterial-causing infectious disease are advancing, and many pharmaceuticals preparations are in actual use. On the other hand, pharmaceutical preparations against infectious disease caused by viruses are not as advanced as the antibacterial agents, under the present circumstances, although causative viruses themselves have been identified with the development in virology in recent years.
For example, against viral infections occurring in farms of fishery product such as fish and shellfish, only vaccines are in actually used against Iridovirus of red sea bream and infectious hematopoietic necrosis virus of salmonid fish and etc. In this field, antiviral agents are still at the stage of research and development, and have not yet been put to practical use.
As literature on antiviral agents in the fishery field, mention can be made of, e.g., Jpn. Pat. Appln. KOKAI Publication No. 1-95792. This publication describes that a substance (46NW-04A) produced by Pseudomonas sp. 46NW-04A (FERM P-9579) has an antiviral activity against viruses such as the salmonid herpes virus (OMV) and the infectious hematopoietic necrosis virus (IHNV).
The above-described substance is also described in Fisheries Science Series 79, “Kaiyo Biseibutu no Seibutsukassei Busshitsu” (Biologically Active Substances of Ocean Microorganisms), supervised by The Japanese Society of Fisheries Science and published by Koseisha Koseikaku Co., Ltd. on Apr. 15, 1990. According to its description, the substance (46NW-04A) having an antiviral activity described in the above publication is referred to as white powder-with the molecular formula C54H95N9O16, having, as constitutive amino acids, 1 threonine residue, 2 serine residues, 1 valine residue, 1 glutamic acid residue, 1 isoleucine residue and 3 leucine residues, and having a 3-hydroxydecanoyl group that is bonded to the N-terminal leucine thereof. It is described therein that the above substance (46NW-04A) has a structure very similar to that of the viscosin reported by Hiramoto et al. (Tetrahedron Letters, vol. 13, pp. 1087-1090, 1970). It is also reported that the microorganism of the genus Pseudomonas producing this substance (46NW-04A) was identified as Pseudomonas fluorescens biovar I.
In addition to the above report, several kinds of analogues to the above-mentioned viscosin have been reported for various objects and uses.
Although a large number of reports on development directed to prevention or treatment against viral diseases of fish have been made, besides the above report, the commercially available pharmaceutical preparations for marine products directed to prevention or treatment of the viral diseases are limited to the vaccines for Iridovirus of red sea bream, salmonid INHV and etc., as described above, and the antiviral agents are not yet put to practical use.